/*
* Copyright (C) 2007 Oracle.  All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#ifndef __BTRFS__
#define __BTRFS__

#include "list.h"
#include "kerncompat.h"
#include "radix-tree.h"
#include "extent-cache.h"
#include "extent_io.h"
//#include "ioctl.h"
#include "btrfs.hpp"
struct btrfs_root;
struct btrfs_trans_handle;
#define BTRFS_MAGIC 0x4D5F53665248425F /* ascii _BHRfS_M, no null */

#define BTRFS_MAX_LEVEL 8

#define BTRFS_COMPAT_EXTENT_TREE_V0

/* holds pointers to all of the tree roots */
#define BTRFS_ROOT_TREE_OBJECTID 1ULL

/* stores information about which extents are in use, and reference counts */
#define BTRFS_EXTENT_TREE_OBJECTID 2ULL

/*
 * chunk tree stores translations from logical -> physical block numbering
 * the super block points to the chunk tree
 */
#define BTRFS_CHUNK_TREE_OBJECTID 3ULL

/*
 * stores information about which areas of a given device are in use.
 * one per device.  The tree of tree roots points to the device tree
 */
#define BTRFS_DEV_TREE_OBJECTID 4ULL

/* one per subvolume, storing files and directories */
#define BTRFS_FS_TREE_OBJECTID 5ULL

/* directory objectid inside the root tree */
#define BTRFS_ROOT_TREE_DIR_OBJECTID 6ULL
/* holds checksums of all the data extents */
#define BTRFS_CSUM_TREE_OBJECTID 7ULL
#define BTRFS_QUOTA_TREE_OBJECTID 8ULL


/* for storing balance parameters in the root tree */
#define BTRFS_BALANCE_OBJECTID -4ULL

/* oprhan objectid for tracking unlinked/truncated files */
#define BTRFS_ORPHAN_OBJECTID -5ULL

/* does write ahead logging to speed up fsyncs */
#define BTRFS_TREE_LOG_OBJECTID -6ULL
#define BTRFS_TREE_LOG_FIXUP_OBJECTID -7ULL

/* space balancing */
#define BTRFS_TREE_RELOC_OBJECTID -8ULL
#define BTRFS_DATA_RELOC_TREE_OBJECTID -9ULL

/*
 * extent checksums all have this objectid
 * this allows them to share the logging tree
 * for fsyncs
 */
#define BTRFS_EXTENT_CSUM_OBJECTID -10ULL

/* For storing free space cache */
#define BTRFS_FREE_SPACE_OBJECTID -11ULL

/*
 * The inode number assigned to the special inode for sotring
 * free ino cache
 */
#define BTRFS_FREE_INO_OBJECTID -12ULL

/* dummy objectid represents multiple objectids */
#define BTRFS_MULTIPLE_OBJECTIDS -255ULL

/*
* All files have objectids in this range.
 */
#define BTRFS_FIRST_FREE_OBJECTID 256ULL
#define BTRFS_LAST_FREE_OBJECTID -256ULL
#define BTRFS_FIRST_CHUNK_TREE_OBJECTID 256ULL



/*
 * the device items go into the chunk tree.  The key is in the form
 * [ 1 BTRFS_DEV_ITEM_KEY device_id ]
 */
#define BTRFS_DEV_ITEMS_OBJECTID 1ULL

/*
 * the max metadata block size.  This limit is somewhat artificial,
 * but the memmove costs go through the roof for larger blocks.
 */
#define BTRFS_MAX_METADATA_BLOCKSIZE 65536

/*
 * we can actually store much bigger names, but lets not confuse the rest
 * of linux
 */
#define BTRFS_NAME_LEN 255

/*
 * Theoretical limit is larger, but we keep this down to a sane
 * value. That should limit greatly the possibility of collisions on
 * inode ref items.
 */
#define BTRFS_LINK_MAX  65535U

/* 32 bytes in various csum fields */
#define BTRFS_CSUM_SIZE 32

/* csum types */
#define BTRFS_CSUM_TYPE_CRC32   0

static int btrfs_csum_sizes[] = { 4, 0 };

/* four bytes for CRC32 */
#define BTRFS_CRC32_SIZE 4
#define BTRFS_EMPTY_DIR_SIZE 0

#define BTRFS_FT_UNKNOWN        0
#define BTRFS_FT_REG_FILE       1
#define BTRFS_FT_DIR            2
#define BTRFS_FT_CHRDEV         3
#define BTRFS_FT_BLKDEV         4
#define BTRFS_FT_FIFO           5
#define BTRFS_FT_SOCK           6
#define BTRFS_FT_SYMLINK        7
#define BTRFS_FT_XATTR          8
#define BTRFS_FT_MAX            9

#define BTRFS_ROOT_SUBVOL_RDONLY        (1ULL << 0)

/*
 * the key defines the order in the tree, and so it also defines (optimal)
 * block layout.  objectid corresonds to the inode number.  The flags
 * tells us things about the object, and is a kind of stream selector.
 * so for a given inode, keys with flags of 1 might refer to the inode
 * data, flags of 2 may point to file data in the btree and flags == 3
 * may point to extents.
 *
 * offset is the starting byte offset for this key in the stream.
 *
 * btrfs_disk_key is in disk byte order.  struct btrfs_key is always
 * in cpu native order.  Otherwise they are identical and their sizes
 * should be the same (ie both packed)
 */
struct btrfs_disk_key {
        __le64 objectid;
        u8 type;
        __le64 offset;
} __attribute__ ((__packed__));

struct btrfs_key {
        u64 objectid;
        u8 type;
        u64 offset;
} __attribute__ ((__packed__));

struct btrfs_mapping_tree {
        struct cache_tree cache_tree;
};

#define BTRFS_UUID_SIZE 16
struct btrfs_dev_item {
        /* the internal btrfs device id */
        __le64 devid;

        /* size of the device */
        __le64 total_bytes;

        /* bytes used */
        __le64 bytes_used;

        /* optimal io alignment for this device */
        __le32 io_align;

        /* optimal io width for this device */
        __le32 io_width;

        /* minimal io size for this device */
        __le32 sector_size;

        /* type and info about this device */
        __le64 type;

        /* expected generation for this device */
        __le64 generation;

        /*
         * starting byte of this partition on the device,
         * to allowr for stripe alignment in the future
         */
        __le64 start_offset;

        /* grouping information for allocation decisions */
        __le32 dev_group;

        /* seek speed 0-100 where 100 is fastest */
        u8 seek_speed;

        /* bandwidth 0-100 where 100 is fastest */
        u8 bandwidth;

        /* btrfs generated uuid for this device */
        u8 uuid[BTRFS_UUID_SIZE];

        /* uuid of FS who owns this device */
        u8 fsid[BTRFS_UUID_SIZE];
} __attribute__ ((__packed__));

struct btrfs_stripe {
        __le64 devid;
        __le64 offset;
        u8 dev_uuid[BTRFS_UUID_SIZE];
} __attribute__ ((__packed__));

struct btrfs_chunk {
        /* size of this chunk in bytes */
        __le64 length;

        /* objectid of the root referencing this chunk */
        __le64 owner;

        __le64 stripe_len;
        __le64 type;

        /* optimal io alignment for this chunk */
        __le32 io_align;

        /* optimal io width for this chunk */
        __le32 io_width;

        /* minimal io size for this chunk */
        __le32 sector_size;

        /* 2^16 stripes is quite a lot, a second limit is the size of a single
         * item in the btree
         */
        __le16 num_stripes;

        /* sub stripes only matter for raid10 */
        __le16 sub_stripes;
        struct btrfs_stripe stripe;
        /* additional stripes go here */
} __attribute__ ((__packed__));

struct btrfs_free_space_header {
        struct btrfs_disk_key location;
        __le64 generation;
        __le64 num_entries;
        __le64 num_bitmaps;
} __attribute__ ((__packed__));

static inline unsigned long btrfs_chunk_item_size(int num_stripes)
{
        BUG_ON(num_stripes == 0);
        return sizeof(struct btrfs_chunk) +
                sizeof(struct btrfs_stripe) * (num_stripes - 1);
}

#define BTRFS_HEADER_FLAG_WRITTEN               (1ULL << 0)
#define BTRFS_HEADER_FLAG_RELOC                 (1ULL << 1)
#define BTRFS_SUPER_FLAG_SEEDING                (1ULL << 32)
#define BTRFS_SUPER_FLAG_METADUMP               (1ULL << 33)

#define BTRFS_BACKREF_REV_MAX           256
#define BTRFS_BACKREF_REV_SHIFT         56
#define BTRFS_BACKREF_REV_MASK          (((u64)BTRFS_BACKREF_REV_MAX - 1) << \
                                         BTRFS_BACKREF_REV_SHIFT)

#define BTRFS_OLD_BACKREF_REV           0
#define BTRFS_MIXED_BACKREF_REV         1

/*
 * every tree block (leaf or node) starts with this header.
 */
struct btrfs_header {
        /* these first four must match the super block */
        u8 csum[BTRFS_CSUM_SIZE];
        u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
        __le64 bytenr; /* which block this node is supposed to live in */
        __le64 flags;

        /* allowed to be different from the super from here on down */
        u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
        __le64 generation;
        __le64 owner;
        __le32 nritems;
        u8 level;
} __attribute__ ((__packed__));

#define BTRFS_NODEPTRS_PER_BLOCK(r) (((r)->nodesize - \
                                sizeof(struct btrfs_header)) / \
                                sizeof(struct btrfs_key_ptr))
#define __BTRFS_LEAF_DATA_SIZE(bs) ((bs) - sizeof(struct btrfs_header))
#define BTRFS_LEAF_DATA_SIZE(r) (__BTRFS_LEAF_DATA_SIZE(r->leafsize))
#define BTRFS_MAX_INLINE_DATA_SIZE(r) (BTRFS_LEAF_DATA_SIZE(r) - \
                                        sizeof(struct btrfs_item) - \
                                        sizeof(struct btrfs_file_extent_item))
#define BTRFS_MAX_XATTR_SIZE(r) (BTRFS_LEAF_DATA_SIZE(r) - \
                                 sizeof(struct btrfs_item) -\
                                 sizeof(struct btrfs_dir_item))


/*
 * this is a very generous portion of the super block, giving us
 * room to translate 14 chunks with 3 stripes each.
 */
#define BTRFS_SYSTEM_CHUNK_ARRAY_SIZE 2048
#define BTRFS_LABEL_SIZE 256

/*
 * just in case we somehow lose the roots and are not able to mount,
 * we store an array of the roots from previous transactions
 * in the super.
 */
#define BTRFS_NUM_BACKUP_ROOTS 4
struct btrfs_root_backup {
        __le64 tree_root;
        __le64 tree_root_gen;

        __le64 chunk_root;
        __le64 chunk_root_gen;

        __le64 extent_root;
        __le64 extent_root_gen;

        __le64 fs_root;
        __le64 fs_root_gen;

        __le64 dev_root;
        __le64 dev_root_gen;

        __le64 csum_root;
        __le64 csum_root_gen;

        __le64 total_bytes;
        __le64 bytes_used;
        __le64 num_devices;
        /* future */
        __le64 unsed_64[4];

        u8 tree_root_level;
        u8 chunk_root_level;
        u8 extent_root_level;
        u8 fs_root_level;
        u8 dev_root_level;
        u8 csum_root_level;
        /* future and to align */
        u8 unused_8[10];
} __attribute__ ((__packed__));

/*
 * the super block basically lists the main trees of the FS
 * it currently lacks any block count etc etc
 */
struct btrfs_super_block {
        u8 csum[BTRFS_CSUM_SIZE];
        /* the first 3 fields must match struct btrfs_header */
        u8 fsid[BTRFS_FSID_SIZE];    /* FS specific uuid */
        __le64 bytenr; /* this block number */
        __le64 flags;

        /* allowed to be different from the btrfs_header from here own down */
        __le64 magic;
        __le64 generation;
        __le64 root;
        __le64 chunk_root;
        __le64 log_root;

        /* this will help find the new super based on the log root */
        __le64 log_root_transid;
        __le64 total_bytes;
        __le64 bytes_used;
        __le64 root_dir_objectid;
        __le64 num_devices;
        __le32 sectorsize;
        __le32 nodesize;
        __le32 leafsize;
        __le32 stripesize;
        __le32 sys_chunk_array_size;
        __le64 chunk_root_generation;
        __le64 compat_flags;
        __le64 compat_ro_flags;
        __le64 incompat_flags;
        __le16 csum_type;
        u8 root_level;
        u8 chunk_root_level;
        u8 log_root_level;
        struct btrfs_dev_item dev_item;

        char label[BTRFS_LABEL_SIZE];

        __le64 cache_generation;

        /* future expansion */
        __le64 reserved[31];
        u8 sys_chunk_array[BTRFS_SYSTEM_CHUNK_ARRAY_SIZE];
        struct btrfs_root_backup super_roots[BTRFS_NUM_BACKUP_ROOTS];
} __attribute__ ((__packed__));

/*
 * Compat flags that we support.  If any incompat flags are set other than the
 * ones specified below then we will fail to mount
 */
#define BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF    (1ULL << 0)
#define BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL   (1ULL << 1)
#define BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS     (1ULL << 2)
#define BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO     (1ULL << 3)

/*
 * some patches floated around with a second compression method
 * lets save that incompat here for when they do get in
 * Note we don't actually support it, we're just reserving the
 * number
 */
#define BTRFS_FEATURE_INCOMPAT_COMPRESS_LZOv2   (1ULL << 4)

/*
 * older kernels tried to do bigger metadata blocks, but the
 * code was pretty buggy.  Lets not let them try anymore.
 */
#define BTRFS_FEATURE_INCOMPAT_BIG_METADATA     (1ULL << 5)
#define BTRFS_FEATURE_INCOMPAT_RAID56           (1ULL << 7)

#define BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF   (1ULL << 6)

#define BTRFS_FEATURE_COMPAT_SUPP               0ULL
#define BTRFS_FEATURE_COMPAT_RO_SUPP            0ULL
#define BTRFS_FEATURE_INCOMPAT_SUPP                     \
        (BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF |         \
         BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL |        \
         BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO |          \
         BTRFS_FEATURE_INCOMPAT_BIG_METADATA |          \
         BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF |         \
         BTRFS_FEATURE_INCOMPAT_RAID56 |                \
         BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)

/*
 * A leaf is full of items. offset and size tell us where to find
 * the item in the leaf (relative to the start of the data area)
 */
struct btrfs_item {
        struct btrfs_disk_key key;
        __le32 offset;
        __le32 size;
} __attribute__ ((__packed__));

/*
 * leaves have an item area and a data area:
 * [item0, item1....itemN] [free space] [dataN...data1, data0]
 *
 * The data is separate from the items to get the keys closer together
 * during searches.
 */
struct btrfs_leaf {
        struct btrfs_header header;
        struct btrfs_item items[];
} __attribute__ ((__packed__));

/*
 * all non-leaf blocks are nodes, they hold only keys and pointers to
 * other blocks
 */
struct btrfs_key_ptr {
        struct btrfs_disk_key key;
        __le64 blockptr;
        __le64 generation;
} __attribute__ ((__packed__));

struct btrfs_node {
        struct btrfs_header header;
        struct btrfs_key_ptr ptrs[];
} __attribute__ ((__packed__));

/*
 * btrfs_paths remember the path taken from the root down to the leaf.
 * level 0 is always the leaf, and nodes[1...BTRFS_MAX_LEVEL] will point
 * to any other levels that are present.
 *
 * The slots array records the index of the item or block pointer
 * used while walking the tree.
 */

struct btrfs_path {
        struct extent_buffer *nodes[BTRFS_MAX_LEVEL];
        int slots[BTRFS_MAX_LEVEL];
        /* if there is real range locking, this locks field will change */
        int locks[BTRFS_MAX_LEVEL];
        int reada;
        /* keep some upper locks as we walk down */
        int lowest_level;

        /*
         * set by btrfs_split_item, tells search_slot to keep all locks
         * and to force calls to keep space in the nodes
         */
        unsigned int search_for_split:1;
        unsigned int keep_locks:1;
        unsigned int skip_locking:1;
        unsigned int leave_spinning:1;
};

/*
 * items in the extent btree are used to record the objectid of the
 * owner of the block and the number of references
 */

struct btrfs_extent_item {
        __le64 refs;
        __le64 generation;
        __le64 flags;
} __attribute__ ((__packed__));

struct btrfs_extent_item_v0 {
        __le32 refs;
} __attribute__ ((__packed__));

#define BTRFS_MAX_EXTENT_ITEM_SIZE(r) ((BTRFS_LEAF_DATA_SIZE(r) >> 4) - \
                                        sizeof(struct btrfs_item))

#define BTRFS_EXTENT_FLAG_DATA          (1ULL << 0)
#define BTRFS_EXTENT_FLAG_TREE_BLOCK    (1ULL << 1)

/* following flags only apply to tree blocks */

/* use full backrefs for extent pointers in the block*/
#define BTRFS_BLOCK_FLAG_FULL_BACKREF   (1ULL << 8)

struct btrfs_tree_block_info {
        struct btrfs_disk_key key;
        u8 level;
} __attribute__ ((__packed__));

struct btrfs_extent_data_ref {
        __le64 root;
        __le64 objectid;
        __le64 offset;
        __le32 count;
} __attribute__ ((__packed__));

struct btrfs_shared_data_ref {
        __le32 count;
} __attribute__ ((__packed__));

struct btrfs_extent_inline_ref {
        u8 type;
        u64 offset;
} __attribute__ ((__packed__));

struct btrfs_extent_ref_v0 {
        __le64 root;
        __le64 generation;
        __le64 objectid;
        __le32 count;
} __attribute__ ((__packed__));

/* dev extents record free space on individual devices.  The owner
 * field points back to the chunk allocation mapping tree that allocated
 * the extent.  The chunk tree uuid field is a way to double check the owner
 */
struct btrfs_dev_extent {
        __le64 chunk_tree;
        __le64 chunk_objectid;
        __le64 chunk_offset;
        __le64 length;
        u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
} __attribute__ ((__packed__));

struct btrfs_inode_ref {
        __le64 index;
        __le16 name_len;
        /* name goes here */
} __attribute__ ((__packed__));

struct btrfs_inode_extref {
        __le64 parent_objectid;
        __le64 index;
        __le16 name_len;
        u8   name[0]; /* name goes here */
} __attribute__ ((__packed__));

struct btrfs_timespec {
        __le64 sec;
        __le32 nsec;
} __attribute__ ((__packed__));

typedef enum {
        BTRFS_COMPRESS_NONE  = 0,
        BTRFS_COMPRESS_ZLIB  = 1,
        BTRFS_COMPRESS_LZO   = 2,
        BTRFS_COMPRESS_TYPES = 2,
        BTRFS_COMPRESS_LAST  = 3
} btrfs_compression_type;

/* we don't understand any encryption methods right now */
typedef enum {
        BTRFS_ENCRYPTION_NONE = 0,
        BTRFS_ENCRYPTION_LAST = 1
} btrfs_encryption_type;

struct btrfs_inode_item {
        /* nfs style generation number */
        __le64 generation;
        /* transid that last touched this inode */
        __le64 transid;
        __le64 size;
        __le64 nbytes;
        __le64 block_group;
        __le32 nlink;
        __le32 uid;
        __le32 gid;
        __le32 mode;
        __le64 rdev;
        __le64 flags;

        /* modification sequence number for NFS */
        __le64 sequence;

        /*
         * a little future expansion, for more than this we can
         * just grow the inode item and version it
         */
        __le64 reserved[4];
        struct btrfs_timespec atime;
        struct btrfs_timespec ctime;
        struct btrfs_timespec mtime;
        struct btrfs_timespec otime;
} __attribute__ ((__packed__));

struct btrfs_dir_log_item {
        __le64 end;
} __attribute__ ((__packed__));

struct btrfs_dir_item {
        struct btrfs_disk_key location;
        __le64 transid;
        __le16 data_len;
        __le16 name_len;
        u8 type;
} __attribute__ ((__packed__));

struct btrfs_root_item_v0 {
        struct btrfs_inode_item inode;
        __le64 generation;
        __le64 root_dirid;
        __le64 bytenr;
        __le64 byte_limit;
        __le64 bytes_used;
        __le64 last_snapshot;
        __le64 flags;
        __le32 refs;
        struct btrfs_disk_key drop_progress;
        u8 drop_level;
        u8 level;
} __attribute__ ((__packed__));

struct btrfs_root_item {
        struct btrfs_inode_item inode;
        __le64 generation;
        __le64 root_dirid;
        __le64 bytenr;
        __le64 byte_limit;
        __le64 bytes_used;
        __le64 last_snapshot;
        __le64 flags;
        __le32 refs;
        struct btrfs_disk_key drop_progress;
        u8 drop_level;
        u8 level;

        /*
         * The following fields appear after subvol_uuids+subvol_times
         * were introduced.
         */

        /*
         * This generation number is used to test if the new fields are valid
         * and up to date while reading the root item. Everytime the root item
         * is written out, the "generation" field is copied into this field. If
         * anyone ever mounted the fs with an older kernel, we will have
         * mismatching generation values here and thus must invalidate the
         * new fields. See btrfs_update_root and btrfs_find_last_root for
         * details.
         * the offset of generation_v2 is also used as the start for the memset
         * when invalidating the fields.
         */
        __le64 generation_v2;
        u8 uuid[BTRFS_UUID_SIZE];
        u8 parent_uuid[BTRFS_UUID_SIZE];
        u8 received_uuid[BTRFS_UUID_SIZE];
        __le64 ctransid; /* updated when an inode changes */
        __le64 otransid; /* trans when created */
        __le64 stransid; /* trans when sent. non-zero for received subvol */
        __le64 rtransid; /* trans when received. non-zero for received subvol */
        struct btrfs_timespec ctime;
        struct btrfs_timespec otime;
        struct btrfs_timespec stime;
        struct btrfs_timespec rtime;
        __le64 reserved[8]; /* for future */
} __attribute__ ((__packed__));

/*
 * this is used for both forward and backward root refs
 */
struct btrfs_root_ref {
        __le64 dirid;
        __le64 sequence;
        __le16 name_len;
} __attribute__ ((__packed__));

#define BTRFS_FILE_EXTENT_INLINE 0
#define BTRFS_FILE_EXTENT_REG 1
#define BTRFS_FILE_EXTENT_PREALLOC 2

struct btrfs_file_extent_item {
        /*
         * transaction id that created this extent
         */
        __le64 generation;
        /*
         * max number of bytes to hold this extent in ram
         * when we split a compressed extent we can't know how big
         * each of the resulting pieces will be.  So, this is
         * an upper limit on the size of the extent in ram instead of
         * an exact limit.
         */
        __le64 ram_bytes;

        /*
         * 32 bits for the various ways we might encode the data,
         * including compression and encryption.  If any of these
         * are set to something a given disk format doesn't understand
         * it is treated like an incompat flag for reading and writing,
         * but not for stat.
         */
        u8 compression;
        u8 encryption;
        __le16 other_encoding; /* spare for later use */

        /* are we inline data or a real extent? */
        u8 type;

        /*
         * disk space consumed by the extent, checksum blocks are included
         * in these numbers
         */
        __le64 disk_bytenr;
        __le64 disk_num_bytes;
        /*
         * the logical offset in file blocks (no csums)
         * this extent record is for.  This allows a file extent to point
         * into the middle of an existing extent on disk, sharing it
         * between two snapshots (useful if some bytes in the middle of the
         * extent have changed
         */
        __le64 offset;
        /*
         * the logical number of file blocks (no csums included)
         */
        __le64 num_bytes;

} __attribute__ ((__packed__));

struct btrfs_csum_item {
        u8 csum;
} __attribute__ ((__packed__));

/* tag for the radix tree of block groups in ram */
#define BTRFS_BLOCK_GROUP_DATA          (1ULL << 0)
#define BTRFS_BLOCK_GROUP_SYSTEM        (1ULL << 1)
#define BTRFS_BLOCK_GROUP_METADATA      (1ULL << 2)
#define BTRFS_BLOCK_GROUP_RAID0         (1ULL << 3)
#define BTRFS_BLOCK_GROUP_RAID1         (1ULL << 4)
#define BTRFS_BLOCK_GROUP_DUP           (1ULL << 5)
#define BTRFS_BLOCK_GROUP_RAID10        (1ULL << 6)
#define BTRFS_BLOCK_GROUP_RAID5    (1ULL << 7)
#define BTRFS_BLOCK_GROUP_RAID6    (1ULL << 8)
#define BTRFS_BLOCK_GROUP_RESERVED      BTRFS_AVAIL_ALLOC_BIT_SINGLE

/* used in struct btrfs_balance_args fields */
#define BTRFS_AVAIL_ALLOC_BIT_SINGLE    (1ULL << 48)

#define BTRFS_QGROUP_STATUS_OFF                 0
#define BTRFS_QGROUP_STATUS_ON                  1
#define BTRFS_QGROUP_STATUS_SCANNING            2

#define BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT   (1 << 0)

struct btrfs_qgroup_status_item {
        __le64 version;
        __le64 generation;
        __le64 flags;
        __le64 scan;            /* progress during scanning */
} __attribute__ ((__packed__));

struct btrfs_block_group_item {
        __le64 used;
        __le64 chunk_objectid;
        __le64 flags;
} __attribute__ ((__packed__));

struct btrfs_qgroup_info_item {
        __le64 generation;
        __le64 referenced;
        __le64 referenced_compressed;
        __le64 exclusive;
        __le64 exclusive_compressed;
} __attribute__ ((__packed__));

/* flags definition for qgroup limits */
#define BTRFS_QGROUP_LIMIT_MAX_RFER     (1ULL << 0)
#define BTRFS_QGROUP_LIMIT_MAX_EXCL     (1ULL << 1)
#define BTRFS_QGROUP_LIMIT_RSV_RFER     (1ULL << 2)
#define BTRFS_QGROUP_LIMIT_RSV_EXCL     (1ULL << 3)
#define BTRFS_QGROUP_LIMIT_RFER_CMPR    (1ULL << 4)
#define BTRFS_QGROUP_LIMIT_EXCL_CMPR    (1ULL << 5)

struct btrfs_qgroup_limit_item {
        __le64 flags;
        __le64 max_referenced;
        __le64 max_exclusive;
        __le64 rsv_referenced;
        __le64 rsv_exclusive;
} __attribute__ ((__packed__));

struct btrfs_space_info {
        u64 flags;
        u64 total_bytes;
        u64 bytes_used;
        u64 bytes_pinned;
        int full;
        struct list_head list;
};

struct btrfs_block_group_cache {
        struct cache_extent cache;
        struct btrfs_key key;
        struct btrfs_block_group_item item;
        struct btrfs_space_info *space_info;
        u64 pinned;
        u64 flags;
        int cached;
        int ro;
};

struct btrfs_extent_ops {
       int (*alloc_extent)(struct btrfs_root *root, u64 num_bytes,
                           u64 hint_byte, struct btrfs_key *ins);
       int (*free_extent)(struct btrfs_root *root, u64 bytenr,
                          u64 num_bytes);
};

struct btrfs_device;
struct btrfs_fs_devices;
struct btrfs_fs_info {
        u8 fsid[BTRFS_FSID_SIZE];
        u8 chunk_tree_uuid[BTRFS_UUID_SIZE];
        struct btrfs_root *fs_root;
        struct btrfs_root *extent_root;
        struct btrfs_root *tree_root;
        struct btrfs_root *chunk_root;
        struct btrfs_root *dev_root;
        struct btrfs_root *csum_root;

        struct cache_tree fs_root_cache;

        /* the log root tree is a directory of all the other log roots */
        struct btrfs_root *log_root_tree;

        struct extent_io_tree extent_cache;
        struct extent_io_tree free_space_cache;
        struct extent_io_tree block_group_cache;
        struct extent_io_tree pinned_extents;
        struct extent_io_tree pending_del;
        struct extent_io_tree extent_ins;

        /* logical->physical extent mapping */
        struct btrfs_mapping_tree mapping_tree;

        u64 generation;
        u64 last_trans_committed;

        u64 avail_data_alloc_bits;
        u64 avail_metadata_alloc_bits;
        u64 avail_system_alloc_bits;
        u64 data_alloc_profile;
        u64 metadata_alloc_profile;
        u64 system_alloc_profile;
        u64 alloc_start;

        struct btrfs_trans_handle *running_transaction;
        struct btrfs_super_block super_copy;
        struct mutex fs_mutex;

        u64 super_bytenr;
        u64 total_pinned;

        struct btrfs_extent_ops *extent_ops;
        struct list_head dirty_cowonly_roots;

        struct btrfs_fs_devices *fs_devices;
        struct list_head space_info;
        int system_allocs;
        int readonly;
        int (*free_extent_hook)(struct btrfs_trans_handle *trans,
                                struct btrfs_root *root,
                                u64 bytenr, u64 num_bytes, u64 parent,
                                u64 root_objectid, u64 owner, u64 offset,
                                int refs_to_drop);
        struct cache_tree *fsck_extent_cache;
        struct cache_tree *corrupt_blocks;
};

/*
 * in ram representation of the tree.  extent_root is used for all allocations
 * and for the extent tree extent_root root.
 */
struct btrfs_root {
        struct extent_buffer *node;
        struct extent_buffer *commit_root;
        struct btrfs_root_item root_item;
        struct btrfs_key root_key;
        struct btrfs_fs_info *fs_info;
        u64 objectid;
        u64 last_trans;

        /* data allocations are done in sectorsize units */
        u32 sectorsize;

        /* node allocations are done in nodesize units */
        u32 nodesize;

        /* leaf allocations are done in leafsize units */
        u32 leafsize;

        /* leaf allocations are done in leafsize units */
        u32 stripesize;

        int ref_cows;
        int track_dirty;


        u32 type;
        u64 highest_inode;
        u64 last_inode_alloc;

        /* the dirty list is only used by non-reference counted roots */
        struct list_head dirty_list;
        struct cache_extent cache;
};

/*
 * inode items have the data typically returned from stat and store other
 * info about object characteristics.  There is one for every file and dir in
 * the FS
 */
#define BTRFS_INODE_ITEM_KEY            1
#define BTRFS_INODE_REF_KEY             12
#define BTRFS_INODE_EXTREF_KEY          13
#define BTRFS_XATTR_ITEM_KEY            24
#define BTRFS_ORPHAN_ITEM_KEY           48

#define BTRFS_DIR_LOG_ITEM_KEY  60
#define BTRFS_DIR_LOG_INDEX_KEY 72
/*
 * dir items are the name -> inode pointers in a directory.  There is one
 * for every name in a directory.
 */
#define BTRFS_DIR_ITEM_KEY      84
#define BTRFS_DIR_INDEX_KEY     96

/*
  * extent data is for file data
  */
 #define BTRFS_EXTENT_DATA_KEY   108

 /*
  * csum items have the checksums for data in the extents
  */
 #define BTRFS_CSUM_ITEM_KEY     120
 /*
  * extent csums are stored in a separate tree and hold csums for
  * an entire extent on disk.
  */
 #define BTRFS_EXTENT_CSUM_KEY   128

 /*
  * root items point to tree roots.  There are typically in the root
  * tree used by the super block to find all the other trees
  */
 #define BTRFS_ROOT_ITEM_KEY     132

 /*
  * root backrefs tie subvols and snapshots to the directory entries that
  * reference them
  */
 #define BTRFS_ROOT_BACKREF_KEY  144

 /*
  * root refs make a fast index for listing all of the snapshots and
  * subvolumes referenced by a given root.  They point directly to the
  * directory item in the root that references the subvol
  */
 #define BTRFS_ROOT_REF_KEY      156

 /*
  * extent items are in the extent map tree.  These record which blocks
  * are used, and how many references there are to each block
  */
 #define BTRFS_EXTENT_ITEM_KEY   168

 #define BTRFS_TREE_BLOCK_REF_KEY        176

 #define BTRFS_EXTENT_DATA_REF_KEY       178

 /* old style extent backrefs */
 #define BTRFS_EXTENT_REF_V0_KEY         180

 #define BTRFS_SHARED_BLOCK_REF_KEY      182

 #define BTRFS_SHARED_DATA_REF_KEY       184


 /*
  * block groups give us hints into the extent allocation trees.  Which
  * blocks are free etc etc
  */
 #define BTRFS_BLOCK_GROUP_ITEM_KEY 192

 #define BTRFS_DEV_EXTENT_KEY    204
 #define BTRFS_DEV_ITEM_KEY      216
 #define BTRFS_CHUNK_ITEM_KEY    228

 #define BTRFS_BALANCE_ITEM_KEY  248

 /*
  * quota groups
  */
 #define BTRFS_QGROUP_STATUS_KEY         240
 #define BTRFS_QGROUP_INFO_KEY           242
 #define BTRFS_QGROUP_LIMIT_KEY          244
 #define BTRFS_QGROUP_RELATION_KEY       246

 /*
  * Persistently stores the io stats in the device tree.
  * One key for all stats, (0, BTRFS_DEV_STATS_KEY, devid).
  */
 #define BTRFS_DEV_STATS_KEY     249

 /*
  * Persistently stores the device replace state in the device tree.
  * The key is built like this: (0, BTRFS_DEV_REPLACE_KEY, 0).
  */
 #define BTRFS_DEV_REPLACE_KEY   250

 /*
  * string items are for debugging.  They just store a short string of
  * data in the FS
  */
 #define BTRFS_STRING_ITEM_KEY   253
 /*
  * Inode flags
  */
 #define BTRFS_INODE_NODATASUM           (1 << 0)
 #define BTRFS_INODE_NODATACOW           (1 << 1)
 #define BTRFS_INODE_READONLY            (1 << 2)

 #define read_eb_member(eb, ptr, type, member, result) (                 \
         read_extent_buffer(eb, (char *)(result),                        \
                            ((unsigned long)(ptr)) +                     \
                             offsetof(type, member),                     \
                            sizeof(((type *)0)->member)))

 #define write_eb_member(eb, ptr, type, member, result) (                \
         write_extent_buffer(eb, (char *)(result),                       \
                            ((unsigned long)(ptr)) +                     \
                             offsetof(type, member),                     \
                            sizeof(((type *)0)->member)))

 #define BTRFS_SETGET_HEADER_FUNCS(name, type, member, bits)             \
 static inline u##bits btrfs_##name(struct extent_buffer *eb)            \
 {                                                                       \
         struct btrfs_header *h = (struct btrfs_header *)eb->data;       \
         return le##bits##_to_cpu(h->member);                            \
 }                                                                       \
 static inline void btrfs_set_##name(struct extent_buffer *eb,           \
                                     u##bits val)                        \
 {                                                                       \
         struct btrfs_header *h = (struct btrfs_header *)eb->data;       \
         h->member = cpu_to_le##bits(val);                               \
 }

 #define BTRFS_SETGET_FUNCS(name, type, member, bits)                    \
 static inline u##bits btrfs_##name(struct extent_buffer *eb,            \
                                    type *s)                             \
 {                                                                       \
         unsigned long offset = (unsigned long)s;                        \
         type *p = (type *) (eb->data + offset);                         \
         return get_unaligned_le##bits(&p->member);                      \
 }                                                                       \
 static inline void btrfs_set_##name(struct extent_buffer *eb,           \
                                     type *s, u##bits val)               \
 {                                                                       \
         unsigned long offset = (unsigned long)s;                        \
         type *p = (type *) (eb->data + offset);                         \
         put_unaligned_le##bits(val, &p->member);                        \
 }

 #define BTRFS_SETGET_STACK_FUNCS(name, type, member, bits)              \
 static inline u##bits btrfs_##name(type *s)                             \
 {                                                                       \
         return le##bits##_to_cpu(s->member);                            \
 }                                                                       \
 static inline void btrfs_set_##name(type *s, u##bits val)               \
 {                                                                       \
         s->member = cpu_to_le##bits(val);                               \
 }

 BTRFS_SETGET_FUNCS(device_type, struct btrfs_dev_item, type, 64)
 BTRFS_SETGET_FUNCS(device_total_bytes, struct btrfs_dev_item, total_bytes, 64)
 BTRFS_SETGET_FUNCS(device_bytes_used, struct btrfs_dev_item, bytes_used, 64)
 BTRFS_SETGET_FUNCS(device_io_align, struct btrfs_dev_item, io_align, 32)
 BTRFS_SETGET_FUNCS(device_io_width, struct btrfs_dev_item, io_width, 32)
 BTRFS_SETGET_FUNCS(device_start_offset, struct btrfs_dev_item,
                    start_offset, 64)
 BTRFS_SETGET_FUNCS(device_sector_size, struct btrfs_dev_item, sector_size, 32)
 BTRFS_SETGET_FUNCS(device_id, struct btrfs_dev_item, devid, 64)
 BTRFS_SETGET_FUNCS(device_group, struct btrfs_dev_item, dev_group, 32)
 BTRFS_SETGET_FUNCS(device_seek_speed, struct btrfs_dev_item, seek_speed, 8)
 BTRFS_SETGET_FUNCS(device_bandwidth, struct btrfs_dev_item, bandwidth, 8)
 BTRFS_SETGET_FUNCS(device_generation, struct btrfs_dev_item, generation, 64)

 BTRFS_SETGET_STACK_FUNCS(stack_device_type, struct btrfs_dev_item, type, 64)
 BTRFS_SETGET_STACK_FUNCS(stack_device_total_bytes, struct btrfs_dev_item,
                          total_bytes, 64)
 BTRFS_SETGET_STACK_FUNCS(stack_device_bytes_used, struct btrfs_dev_item,
                          bytes_used, 64)
 BTRFS_SETGET_STACK_FUNCS(stack_device_io_align, struct btrfs_dev_item,
                          io_align, 32)
 BTRFS_SETGET_STACK_FUNCS(stack_device_io_width, struct btrfs_dev_item,
                          io_width, 32)
 BTRFS_SETGET_STACK_FUNCS(stack_device_sector_size, struct btrfs_dev_item,
                          sector_size, 32)
 BTRFS_SETGET_STACK_FUNCS(stack_device_id, struct btrfs_dev_item, devid, 64)
 BTRFS_SETGET_STACK_FUNCS(stack_device_group, struct btrfs_dev_item,
                          dev_group, 32)
 BTRFS_SETGET_STACK_FUNCS(stack_device_seek_speed, struct btrfs_dev_item,
                          seek_speed, 8)
 BTRFS_SETGET_STACK_FUNCS(stack_device_bandwidth, struct btrfs_dev_item,
                          bandwidth, 8)
 BTRFS_SETGET_STACK_FUNCS(stack_device_generation, struct btrfs_dev_item,
                          generation, 64)

 static inline char *btrfs_device_uuid(struct btrfs_dev_item *d)
 {
         return (char *)d + offsetof(struct btrfs_dev_item, uuid);
 }

 static inline char *btrfs_device_fsid(struct btrfs_dev_item *d)
 {
         return (char *)d + offsetof(struct btrfs_dev_item, fsid);
 }

 BTRFS_SETGET_FUNCS(chunk_length, struct btrfs_chunk, length, 64)
 BTRFS_SETGET_FUNCS(chunk_owner, struct btrfs_chunk, owner, 64)
 BTRFS_SETGET_FUNCS(chunk_stripe_len, struct btrfs_chunk, stripe_len, 64)
 BTRFS_SETGET_FUNCS(chunk_io_align, struct btrfs_chunk, io_align, 32)
 BTRFS_SETGET_FUNCS(chunk_io_width, struct btrfs_chunk, io_width, 32)
 BTRFS_SETGET_FUNCS(chunk_sector_size, struct btrfs_chunk, sector_size, 32)
 BTRFS_SETGET_FUNCS(chunk_type, struct btrfs_chunk, type, 64)
 BTRFS_SETGET_FUNCS(chunk_num_stripes, struct btrfs_chunk, num_stripes, 16)
 BTRFS_SETGET_FUNCS(chunk_sub_stripes, struct btrfs_chunk, sub_stripes, 16)
 BTRFS_SETGET_FUNCS(stripe_devid, struct btrfs_stripe, devid, 64)
 BTRFS_SETGET_FUNCS(stripe_offset, struct btrfs_stripe, offset, 64)

 static inline char *btrfs_stripe_dev_uuid(struct btrfs_stripe *s)
 {
         return (char *)s + offsetof(struct btrfs_stripe, dev_uuid);
 }

 BTRFS_SETGET_STACK_FUNCS(stack_chunk_length, struct btrfs_chunk, length, 64)
 BTRFS_SETGET_STACK_FUNCS(stack_chunk_owner, struct btrfs_chunk, owner, 64)
 BTRFS_SETGET_STACK_FUNCS(stack_chunk_stripe_len, struct btrfs_chunk,
                          stripe_len, 64)
 BTRFS_SETGET_STACK_FUNCS(stack_chunk_io_align, struct btrfs_chunk,
                          io_align, 32)
 BTRFS_SETGET_STACK_FUNCS(stack_chunk_io_width, struct btrfs_chunk,
                          io_width, 32)
 BTRFS_SETGET_STACK_FUNCS(stack_chunk_sector_size, struct btrfs_chunk,
                          sector_size, 32)
 BTRFS_SETGET_STACK_FUNCS(stack_chunk_type, struct btrfs_chunk, type, 64)
 BTRFS_SETGET_STACK_FUNCS(stack_chunk_num_stripes, struct btrfs_chunk,
                          num_stripes, 16)
 BTRFS_SETGET_STACK_FUNCS(stack_chunk_sub_stripes, struct btrfs_chunk,
                          sub_stripes, 16)
 BTRFS_SETGET_STACK_FUNCS(stack_stripe_devid, struct btrfs_stripe, devid, 64)
 BTRFS_SETGET_STACK_FUNCS(stack_stripe_offset, struct btrfs_stripe, offset, 64)

 static inline struct btrfs_stripe *btrfs_stripe_nr(struct btrfs_chunk *c,
                                                    int nr)
 {
         unsigned long offset = (unsigned long)c;
         offset += offsetof(struct btrfs_chunk, stripe);
         offset += nr * sizeof(struct btrfs_stripe);
         return (struct btrfs_stripe *)offset;
 }

 static inline char *btrfs_stripe_dev_uuid_nr(struct btrfs_chunk *c, int nr)
 {
         return btrfs_stripe_dev_uuid(btrfs_stripe_nr(c, nr));
 }

 static inline u64 btrfs_stripe_offset_nr(struct extent_buffer *eb,
                                          struct btrfs_chunk *c, int nr)
 {
         return btrfs_stripe_offset(eb, btrfs_stripe_nr(c, nr));
 }

 static inline void btrfs_set_stripe_offset_nr(struct extent_buffer *eb,
                                              struct btrfs_chunk *c, int nr,
                                              u64 val)
 {
         btrfs_set_stripe_offset(eb, btrfs_stripe_nr(c, nr), val);
 }

 static inline u64 btrfs_stripe_devid_nr(struct extent_buffer *eb,
                                          struct btrfs_chunk *c, int nr)
 {
         return btrfs_stripe_devid(eb, btrfs_stripe_nr(c, nr));
 }

 static inline void btrfs_set_stripe_devid_nr(struct extent_buffer *eb,
                                              struct btrfs_chunk *c, int nr,
                                              u64 val)
 {
         btrfs_set_stripe_devid(eb, btrfs_stripe_nr(c, nr), val);
 }

 /* struct btrfs_block_group_item */
 BTRFS_SETGET_STACK_FUNCS(block_group_used, struct btrfs_block_group_item,
                          used, 64)
 BTRFS_SETGET_FUNCS(disk_block_group_used, struct btrfs_block_group_item,
                          used, 64)
 BTRFS_SETGET_STACK_FUNCS(block_group_chunk_objectid,
                         struct btrfs_block_group_item, chunk_objectid, 64)

 BTRFS_SETGET_FUNCS(disk_block_group_chunk_objectid,
                    struct btrfs_block_group_item, chunk_objectid, 64)
 BTRFS_SETGET_FUNCS(disk_block_group_flags,
                    struct btrfs_block_group_item, flags, 64)
 BTRFS_SETGET_STACK_FUNCS(block_group_flags,
                         struct btrfs_block_group_item, flags, 64)

 /* struct btrfs_inode_ref */
 BTRFS_SETGET_FUNCS(inode_ref_name_len, struct btrfs_inode_ref, name_len, 16)
 BTRFS_SETGET_STACK_FUNCS(stack_inode_ref_name_len, struct btrfs_inode_ref, name_len, 16)
 BTRFS_SETGET_FUNCS(inode_ref_index, struct btrfs_inode_ref, index, 64)

 /* struct btrfs_inode_extref */
 BTRFS_SETGET_FUNCS(inode_extref_parent, struct btrfs_inode_extref,
                    parent_objectid, 64)
 BTRFS_SETGET_FUNCS(inode_extref_name_len, struct btrfs_inode_extref,
                    name_len, 16)
 BTRFS_SETGET_FUNCS(inode_extref_index, struct btrfs_inode_extref, index, 64)

 /* struct btrfs_inode_item */
 BTRFS_SETGET_FUNCS(inode_generation, struct btrfs_inode_item, generation, 64)
 BTRFS_SETGET_FUNCS(inode_sequence, struct btrfs_inode_item, sequence, 64)
 BTRFS_SETGET_FUNCS(inode_transid, struct btrfs_inode_item, transid, 64)
 BTRFS_SETGET_FUNCS(inode_size, struct btrfs_inode_item, size, 64)
 BTRFS_SETGET_FUNCS(inode_nbytes, struct btrfs_inode_item, nbytes, 64)
 BTRFS_SETGET_FUNCS(inode_block_group, struct btrfs_inode_item, block_group, 64)
 BTRFS_SETGET_FUNCS(inode_nlink, struct btrfs_inode_item, nlink, 32)
 BTRFS_SETGET_FUNCS(inode_uid, struct btrfs_inode_item, uid, 32)
 BTRFS_SETGET_FUNCS(inode_gid, struct btrfs_inode_item, gid, 32)
 BTRFS_SETGET_FUNCS(inode_mode, struct btrfs_inode_item, mode, 32)
 BTRFS_SETGET_FUNCS(inode_rdev, struct btrfs_inode_item, rdev, 64)
 BTRFS_SETGET_FUNCS(inode_flags, struct btrfs_inode_item, flags, 64)

 BTRFS_SETGET_STACK_FUNCS(stack_inode_generation,
                          struct btrfs_inode_item, generation, 64)
 BTRFS_SETGET_STACK_FUNCS(stack_inode_sequence,
                          struct btrfs_inode_item, generation, 64)
 BTRFS_SETGET_STACK_FUNCS(stack_inode_size,
                          struct btrfs_inode_item, size, 64)
 BTRFS_SETGET_STACK_FUNCS(stack_inode_nbytes,
                          struct btrfs_inode_item, nbytes, 64)
 BTRFS_SETGET_STACK_FUNCS(stack_inode_block_group,
                          struct btrfs_inode_item, block_group, 64)
 BTRFS_SETGET_STACK_FUNCS(stack_inode_nlink,
                          struct btrfs_inode_item, nlink, 32)
 BTRFS_SETGET_STACK_FUNCS(stack_inode_uid,
                          struct btrfs_inode_item, uid, 32)
 BTRFS_SETGET_STACK_FUNCS(stack_inode_gid,
                          struct btrfs_inode_item, gid, 32)
 BTRFS_SETGET_STACK_FUNCS(stack_inode_mode,
                          struct btrfs_inode_item, mode, 32)
 BTRFS_SETGET_STACK_FUNCS(stack_inode_rdev,
                          struct btrfs_inode_item, rdev, 64)
 BTRFS_SETGET_STACK_FUNCS(stack_inode_flags,
                          struct btrfs_inode_item, flags, 64)

 static inline struct btrfs_timespec *
 btrfs_inode_atime(struct btrfs_inode_item *inode_item)
 {
         unsigned long ptr = (unsigned long)inode_item;
         ptr += offsetof(struct btrfs_inode_item, atime);
         return (struct btrfs_timespec *)ptr;
 }

 static inline struct btrfs_timespec *
 btrfs_inode_mtime(struct btrfs_inode_item *inode_item)
 {
         unsigned long ptr = (unsigned long)inode_item;
         ptr += offsetof(struct btrfs_inode_item, mtime);
         return (struct btrfs_timespec *)ptr;
 }

 static inline struct btrfs_timespec *
 btrfs_inode_ctime(struct btrfs_inode_item *inode_item)
 {
         unsigned long ptr = (unsigned long)inode_item;
         ptr += offsetof(struct btrfs_inode_item, ctime);
         return (struct btrfs_timespec *)ptr;
 }

 static inline struct btrfs_timespec *
 btrfs_inode_otime(struct btrfs_inode_item *inode_item)
 {
         unsigned long ptr = (unsigned long)inode_item;
         ptr += offsetof(struct btrfs_inode_item, otime);
         return (struct btrfs_timespec *)ptr;
 }

 BTRFS_SETGET_FUNCS(timespec_sec, struct btrfs_timespec, sec, 64)
 BTRFS_SETGET_FUNCS(timespec_nsec, struct btrfs_timespec, nsec, 32)
 BTRFS_SETGET_STACK_FUNCS(stack_timespec_sec, struct btrfs_timespec,
                          sec, 64)
 BTRFS_SETGET_STACK_FUNCS(stack_timespec_nsec, struct btrfs_timespec,
                          nsec, 32)

 /* struct btrfs_dev_extent */
 BTRFS_SETGET_FUNCS(dev_extent_chunk_tree, struct btrfs_dev_extent,
                    chunk_tree, 64)
 BTRFS_SETGET_FUNCS(dev_extent_chunk_objectid, struct btrfs_dev_extent,
                    chunk_objectid, 64)
 BTRFS_SETGET_FUNCS(dev_extent_chunk_offset, struct btrfs_dev_extent,
                    chunk_offset, 64)
 BTRFS_SETGET_FUNCS(dev_extent_length, struct btrfs_dev_extent, length, 64)

 static inline u8 *btrfs_dev_extent_chunk_tree_uuid(struct btrfs_dev_extent *dev)
 {
         unsigned long ptr = offsetof(struct btrfs_dev_extent, chunk_tree_uuid);
         return (u8 *)((unsigned long)dev + ptr);
 }


 /* struct btrfs_extent_item */
 BTRFS_SETGET_FUNCS(extent_refs, struct btrfs_extent_item, refs, 64)
 BTRFS_SETGET_FUNCS(extent_generation, struct btrfs_extent_item,
                    generation, 64)
 BTRFS_SETGET_FUNCS(extent_flags, struct btrfs_extent_item, flags, 64)

 BTRFS_SETGET_FUNCS(extent_refs_v0, struct btrfs_extent_item_v0, refs, 32)

 BTRFS_SETGET_FUNCS(tree_block_level, struct btrfs_tree_block_info, level, 8)

 static inline void btrfs_tree_block_key(struct extent_buffer *eb,
                                         struct btrfs_tree_block_info *item,
                                         struct btrfs_disk_key *key)
 {
         read_eb_member(eb, item, struct btrfs_tree_block_info, key, key);
 }

 static inline void btrfs_set_tree_block_key(struct extent_buffer *eb,
                                             struct btrfs_tree_block_info *item,
                                             struct btrfs_disk_key *key)
 {
         write_eb_member(eb, item, struct btrfs_tree_block_info, key, key);
 }

 BTRFS_SETGET_FUNCS(extent_data_ref_root, struct btrfs_extent_data_ref,
                    root, 64)
 BTRFS_SETGET_FUNCS(extent_data_ref_objectid, struct btrfs_extent_data_ref,
                    objectid, 64)
 BTRFS_SETGET_FUNCS(extent_data_ref_offset, struct btrfs_extent_data_ref,
                    offset, 64)
 BTRFS_SETGET_FUNCS(extent_data_ref_count, struct btrfs_extent_data_ref,
                    count, 32)

 BTRFS_SETGET_FUNCS(shared_data_ref_count, struct btrfs_shared_data_ref,
                    count, 32)

 BTRFS_SETGET_FUNCS(extent_inline_ref_type, struct btrfs_extent_inline_ref,
                    type, 8)
 BTRFS_SETGET_FUNCS(extent_inline_ref_offset, struct btrfs_extent_inline_ref,
                    offset, 64)

 static inline u32 btrfs_extent_inline_ref_size(int type)
 {
         if (type == BTRFS_TREE_BLOCK_REF_KEY ||
             type == BTRFS_SHARED_BLOCK_REF_KEY)
                 return sizeof(struct btrfs_extent_inline_ref);
         if (type == BTRFS_SHARED_DATA_REF_KEY)
                 return sizeof(struct btrfs_shared_data_ref) +
                        sizeof(struct btrfs_extent_inline_ref);
         if (type == BTRFS_EXTENT_DATA_REF_KEY)
                 return sizeof(struct btrfs_extent_data_ref) +
                        offsetof(struct btrfs_extent_inline_ref, offset);
         BUG();
         return 0;
 }

 BTRFS_SETGET_FUNCS(ref_root_v0, struct btrfs_extent_ref_v0, root, 64)
 BTRFS_SETGET_FUNCS(ref_generation_v0, struct btrfs_extent_ref_v0,
                    generation, 64)
 BTRFS_SETGET_FUNCS(ref_objectid_v0, struct btrfs_extent_ref_v0, objectid, 64)
 BTRFS_SETGET_FUNCS(ref_count_v0, struct btrfs_extent_ref_v0, count, 32)

 /* struct btrfs_node */
 BTRFS_SETGET_FUNCS(key_blockptr, struct btrfs_key_ptr, blockptr, 64)
 BTRFS_SETGET_FUNCS(key_generation, struct btrfs_key_ptr, generation, 64)

 static inline u64 btrfs_node_blockptr(struct extent_buffer *eb, int nr)
 {
         unsigned long ptr;
         ptr = offsetof(struct btrfs_node, ptrs) +
                 sizeof(struct btrfs_key_ptr) * nr;
         return btrfs_key_blockptr(eb, (struct btrfs_key_ptr *)ptr);
 }

 static inline void btrfs_set_node_blockptr(struct extent_buffer *eb,
                                            int nr, u64 val)
 {
         unsigned long ptr;
         ptr = offsetof(struct btrfs_node, ptrs) +
                 sizeof(struct btrfs_key_ptr) * nr;
         btrfs_set_key_blockptr(eb, (struct btrfs_key_ptr *)ptr, val);
 }

 static inline u64 btrfs_node_ptr_generation(struct extent_buffer *eb, int nr)
 {
         unsigned long ptr;
         ptr = offsetof(struct btrfs_node, ptrs) +
                 sizeof(struct btrfs_key_ptr) * nr;
         return btrfs_key_generation(eb, (struct btrfs_key_ptr *)ptr);
 }

 static inline void btrfs_set_node_ptr_generation(struct extent_buffer *eb,
                                                  int nr, u64 val)
 {
         unsigned long ptr;
         ptr = offsetof(struct btrfs_node, ptrs) +
                 sizeof(struct btrfs_key_ptr) * nr;
         btrfs_set_key_generation(eb, (struct btrfs_key_ptr *)ptr, val);
 }

 static inline unsigned long btrfs_node_key_ptr_offset(int nr)
 {
         return offsetof(struct btrfs_node, ptrs) +
                 sizeof(struct btrfs_key_ptr) * nr;
 }

 static inline void btrfs_node_key(struct extent_buffer *eb,
                                   struct btrfs_disk_key *disk_key, int nr)
 {
         unsigned long ptr;
         ptr = btrfs_node_key_ptr_offset(nr);
         read_eb_member(eb, (struct btrfs_key_ptr *)ptr,
                        struct btrfs_key_ptr, key, disk_key);
 }

 static inline void btrfs_set_node_key(struct extent_buffer *eb,
                                       struct btrfs_disk_key *disk_key, int nr)
 {
         unsigned long ptr;
         ptr = btrfs_node_key_ptr_offset(nr);
         write_eb_member(eb, (struct btrfs_key_ptr *)ptr,
                        struct btrfs_key_ptr, key, disk_key);
 }

 /* struct btrfs_item */
 BTRFS_SETGET_FUNCS(item_offset, struct btrfs_item, offset, 32)
 BTRFS_SETGET_FUNCS(item_size, struct btrfs_item, size, 32)

 static inline unsigned long btrfs_item_nr_offset(int nr)
 {
         return offsetof(struct btrfs_leaf, items) +
                 sizeof(struct btrfs_item) * nr;
 }

 static inline struct btrfs_item *btrfs_item_nr(struct extent_buffer *,
                                                int nr)
 {
         return (struct btrfs_item *)btrfs_item_nr_offset(nr);
 }

 static inline u32 btrfs_item_end(struct extent_buffer *eb,
                                  struct btrfs_item *item)
 {
         return btrfs_item_offset(eb, item) + btrfs_item_size(eb, item);
 }

 static inline u32 btrfs_item_end_nr(struct extent_buffer *eb, int nr)
 {
         return btrfs_item_end(eb, btrfs_item_nr(eb, nr));
 }

 static inline u32 btrfs_item_offset_nr(struct extent_buffer *eb, int nr)
 {
         return btrfs_item_offset(eb, btrfs_item_nr(eb, nr));
 }

 static inline u32 btrfs_item_size_nr(struct extent_buffer *eb, int nr)
 {
         return btrfs_item_size(eb, btrfs_item_nr(eb, nr));
 }

 static inline void btrfs_item_key(struct extent_buffer *eb,
                            struct btrfs_disk_key *disk_key, int nr)
 {
         struct btrfs_item *item = btrfs_item_nr(eb, nr);
         read_eb_member(eb, item, struct btrfs_item, key, disk_key);
 }

 static inline void btrfs_set_item_key(struct extent_buffer *eb,
                                struct btrfs_disk_key *disk_key, int nr)
 {
         struct btrfs_item *item = btrfs_item_nr(eb, nr);
         write_eb_member(eb, item, struct btrfs_item, key, disk_key);
 }

 BTRFS_SETGET_FUNCS(dir_log_end, struct btrfs_dir_log_item, end, 64)

 /*
  * struct btrfs_root_ref
  */
 BTRFS_SETGET_FUNCS(root_ref_dirid, struct btrfs_root_ref, dirid, 64)
 BTRFS_SETGET_FUNCS(root_ref_sequence, struct btrfs_root_ref, sequence, 64)
 BTRFS_SETGET_FUNCS(root_ref_name_len, struct btrfs_root_ref, name_len, 16)

 BTRFS_SETGET_STACK_FUNCS(stack_root_ref_dirid, struct btrfs_root_ref, dirid, 64)
 BTRFS_SETGET_STACK_FUNCS(stack_root_ref_sequence, struct btrfs_root_ref, sequence, 64)
 BTRFS_SETGET_STACK_FUNCS(stack_root_ref_name_len, struct btrfs_root_ref, name_len, 16)

 /* struct btrfs_dir_item */
 BTRFS_SETGET_FUNCS(dir_data_len, struct btrfs_dir_item, data_len, 16)
 BTRFS_SETGET_FUNCS(dir_type, struct btrfs_dir_item, type, 8)
 BTRFS_SETGET_FUNCS(dir_name_len, struct btrfs_dir_item, name_len, 16)
 BTRFS_SETGET_FUNCS(dir_transid, struct btrfs_dir_item, transid, 64)
 BTRFS_SETGET_STACK_FUNCS(stack_dir_name_len, struct btrfs_dir_item, name_len, 16)

 static inline void btrfs_dir_item_key(struct extent_buffer *eb,
                                       struct btrfs_dir_item *item,
                                       struct btrfs_disk_key *key)
 {
         read_eb_member(eb, item, struct btrfs_dir_item, location, key);
 }

 static inline void btrfs_set_dir_item_key(struct extent_buffer *eb,
                                           struct btrfs_dir_item *item,
                                           struct btrfs_disk_key *key)
 {
         write_eb_member(eb, item, struct btrfs_dir_item, location, key);
 }

 /* struct btrfs_free_space_header */
 BTRFS_SETGET_FUNCS(free_space_entries, struct btrfs_free_space_header,
                    num_entries, 64)
 BTRFS_SETGET_FUNCS(free_space_bitmaps, struct btrfs_free_space_header,
                    num_bitmaps, 64)
 BTRFS_SETGET_FUNCS(free_space_generation, struct btrfs_free_space_header,
                    generation, 64)

 static inline void btrfs_free_space_key(struct extent_buffer *eb,
                                         struct btrfs_free_space_header *h,
                                         struct btrfs_disk_key *key)
 {
         read_eb_member(eb, h, struct btrfs_free_space_header, location, key);
 }

 static inline void btrfs_set_free_space_key(struct extent_buffer *eb,
                                             struct btrfs_free_space_header *h,
                                             struct btrfs_disk_key *key)
 {
         write_eb_member(eb, h, struct btrfs_free_space_header, location, key);
 }

 /* struct btrfs_disk_key */
 BTRFS_SETGET_STACK_FUNCS(disk_key_objectid, struct btrfs_disk_key,
                          objectid, 64)
 BTRFS_SETGET_STACK_FUNCS(disk_key_offset, struct btrfs_disk_key, offset, 64)
 BTRFS_SETGET_STACK_FUNCS(disk_key_type, struct btrfs_disk_key, type, 8)

 static inline void btrfs_disk_key_to_cpu(struct btrfs_key *cpu,
                                          struct btrfs_disk_key *disk)
 {
         cpu->offset = le64_to_cpu(disk->offset);
         cpu->type = disk->type;
         cpu->objectid = le64_to_cpu(disk->objectid);
 }

 static inline void btrfs_cpu_key_to_disk(struct btrfs_disk_key *disk,
                                          struct btrfs_key *cpu)
 {
         disk->offset = cpu_to_le64(cpu->offset);
         disk->type = cpu->type;
         disk->objectid = cpu_to_le64(cpu->objectid);
 }

 static inline void btrfs_node_key_to_cpu(struct extent_buffer *eb,
                                   struct btrfs_key *key, int nr)
 {
         struct btrfs_disk_key disk_key;
         btrfs_node_key(eb, &disk_key, nr);
         btrfs_disk_key_to_cpu(key, &disk_key);
 }

 static inline void btrfs_item_key_to_cpu(struct extent_buffer *eb,
                                   struct btrfs_key *key, int nr)
 {
         struct btrfs_disk_key disk_key;
         btrfs_item_key(eb, &disk_key, nr);
         btrfs_disk_key_to_cpu(key, &disk_key);
 }

 static inline void btrfs_dir_item_key_to_cpu(struct extent_buffer *eb,
                                       struct btrfs_dir_item *item,
                                       struct btrfs_key *key)
 {
         struct btrfs_disk_key disk_key;
         btrfs_dir_item_key(eb, item, &disk_key);
         btrfs_disk_key_to_cpu(key, &disk_key);
 }


 static inline u8 btrfs_key_type(struct btrfs_key *key)
 {
         return key->type;
 }

 static inline void btrfs_set_key_type(struct btrfs_key *key, u8 val)
 {
         key->type = val;
 }

 /* struct btrfs_header */
 BTRFS_SETGET_HEADER_FUNCS(header_bytenr, struct btrfs_header, bytenr, 64)
 BTRFS_SETGET_HEADER_FUNCS(header_generation, struct btrfs_header,
                           generation, 64)
 BTRFS_SETGET_HEADER_FUNCS(header_owner, struct btrfs_header, owner, 64)
 BTRFS_SETGET_HEADER_FUNCS(header_nritems, struct btrfs_header, nritems, 32)
 BTRFS_SETGET_HEADER_FUNCS(header_flags, struct btrfs_header, flags, 64)
 BTRFS_SETGET_HEADER_FUNCS(header_level, struct btrfs_header, level, 8)

 static inline int btrfs_header_flag(struct extent_buffer *eb, u64 flag)
 {
         return (btrfs_header_flags(eb) & flag) == flag;
 }

 static inline int btrfs_set_header_flag(struct extent_buffer *eb, u64 flag)
 {
         u64 flags = btrfs_header_flags(eb);
         btrfs_set_header_flags(eb, flags | flag);
         return (flags & flag) == flag;
 }

 static inline int btrfs_clear_header_flag(struct extent_buffer *eb, u64 flag)
 {
         u64 flags = btrfs_header_flags(eb);
         btrfs_set_header_flags(eb, flags & ~flag);
         return (flags & flag) == flag;
 }

 static inline int btrfs_header_backref_rev(struct extent_buffer *eb)
 {
         u64 flags = btrfs_header_flags(eb);
         return flags >> BTRFS_BACKREF_REV_SHIFT;
 }

 static inline void btrfs_set_header_backref_rev(struct extent_buffer *eb,
                                                 int rev)
 {
         u64 flags = btrfs_header_flags(eb);
         flags &= ~BTRFS_BACKREF_REV_MASK;
         flags |= (u64)rev << BTRFS_BACKREF_REV_SHIFT;
         btrfs_set_header_flags(eb, flags);
 }

 static inline u8 *btrfs_header_fsid(struct extent_buffer*)
 {
         unsigned long ptr = offsetof(struct btrfs_header, fsid);
         return (u8 *)ptr;
 }

 static inline u8 *btrfs_header_chunk_tree_uuid(struct extent_buffer)
 {
         unsigned long ptr = offsetof(struct btrfs_header, chunk_tree_uuid);
         return (u8 *)ptr;
 }

 static inline u8 *btrfs_super_fsid(struct extent_buffer *)
 {
         unsigned long ptr = offsetof(struct btrfs_super_block, fsid);
         return (u8 *)ptr;
 }

 static inline u8 *btrfs_header_csum(struct extent_buffer *)
 {
         unsigned long ptr = offsetof(struct btrfs_header, csum);
         return (u8 *)ptr;
 }

 static inline struct btrfs_node *btrfs_buffer_node(struct extent_buffer *)
 {
         return NULL;
 }

 static inline struct btrfs_leaf *btrfs_buffer_leaf(struct extent_buffer *)
 {
         return NULL;
 }

 static inline struct btrfs_header *btrfs_buffer_header(struct extent_buffer *)
 {
         return NULL;
 }

 static inline int btrfs_is_leaf(struct extent_buffer *eb)
 {
         return (btrfs_header_level(eb) == 0);
 }

 /* struct btrfs_root_item */
 BTRFS_SETGET_FUNCS(disk_root_generation, struct btrfs_root_item,
                    generation, 64)
 BTRFS_SETGET_FUNCS(disk_root_refs, struct btrfs_root_item, refs, 32)
 BTRFS_SETGET_FUNCS(disk_root_bytenr, struct btrfs_root_item, bytenr, 64)
 BTRFS_SETGET_FUNCS(disk_root_level, struct btrfs_root_item, level, 8)

 BTRFS_SETGET_STACK_FUNCS(root_generation, struct btrfs_root_item,
                          generation, 64)
 BTRFS_SETGET_STACK_FUNCS(root_bytenr, struct btrfs_root_item, bytenr, 64)
 BTRFS_SETGET_STACK_FUNCS(root_level, struct btrfs_root_item, level, 8)
 BTRFS_SETGET_STACK_FUNCS(root_dirid, struct btrfs_root_item, root_dirid, 64)
 BTRFS_SETGET_STACK_FUNCS(root_refs, struct btrfs_root_item, refs, 32)
 BTRFS_SETGET_STACK_FUNCS(root_flags, struct btrfs_root_item, flags, 64)
 BTRFS_SETGET_STACK_FUNCS(root_used, struct btrfs_root_item, bytes_used, 64)
 BTRFS_SETGET_STACK_FUNCS(root_limit, struct btrfs_root_item, byte_limit, 64)
 BTRFS_SETGET_STACK_FUNCS(root_last_snapshot, struct btrfs_root_item,
                          last_snapshot, 64)
 BTRFS_SETGET_STACK_FUNCS(root_generation_v2, struct btrfs_root_item,
                          generation_v2, 64)
 BTRFS_SETGET_STACK_FUNCS(root_ctransid, struct btrfs_root_item,
                          ctransid, 64)
 BTRFS_SETGET_STACK_FUNCS(root_otransid, struct btrfs_root_item,
                          otransid, 64)
 BTRFS_SETGET_STACK_FUNCS(root_stransid, struct btrfs_root_item,
                          stransid, 64)
 BTRFS_SETGET_STACK_FUNCS(root_rtransid, struct btrfs_root_item,
                          rtransid, 64)

 /* struct btrfs_root_backup */
 BTRFS_SETGET_STACK_FUNCS(backup_tree_root, struct btrfs_root_backup,
                    tree_root, 64)
 BTRFS_SETGET_STACK_FUNCS(backup_tree_root_gen, struct btrfs_root_backup,
                    tree_root_gen, 64)
 BTRFS_SETGET_STACK_FUNCS(backup_tree_root_level, struct btrfs_root_backup,
                    tree_root_level, 8)

 BTRFS_SETGET_STACK_FUNCS(backup_chunk_root, struct btrfs_root_backup,
                    chunk_root, 64)
 BTRFS_SETGET_STACK_FUNCS(backup_chunk_root_gen, struct btrfs_root_backup,
                    chunk_root_gen, 64)
 BTRFS_SETGET_STACK_FUNCS(backup_chunk_root_level, struct btrfs_root_backup,
                    chunk_root_level, 8)

 BTRFS_SETGET_STACK_FUNCS(backup_extent_root, struct btrfs_root_backup,
                    extent_root, 64)
 BTRFS_SETGET_STACK_FUNCS(backup_extent_root_gen, struct btrfs_root_backup,
                    extent_root_gen, 64)
 BTRFS_SETGET_STACK_FUNCS(backup_extent_root_level, struct btrfs_root_backup,
                    extent_root_level, 8)

 BTRFS_SETGET_STACK_FUNCS(backup_fs_root, struct btrfs_root_backup,
                    fs_root, 64)
 BTRFS_SETGET_STACK_FUNCS(backup_fs_root_gen, struct btrfs_root_backup,
                    fs_root_gen, 64)
 BTRFS_SETGET_STACK_FUNCS(backup_fs_root_level, struct btrfs_root_backup,
                    fs_root_level, 8)

 BTRFS_SETGET_STACK_FUNCS(backup_dev_root, struct btrfs_root_backup,
                    dev_root, 64)
 BTRFS_SETGET_STACK_FUNCS(backup_dev_root_gen, struct btrfs_root_backup,
                    dev_root_gen, 64)
 BTRFS_SETGET_STACK_FUNCS(backup_dev_root_level, struct btrfs_root_backup,
                    dev_root_level, 8)

 BTRFS_SETGET_STACK_FUNCS(backup_csum_root, struct btrfs_root_backup,
                    csum_root, 64)
 BTRFS_SETGET_STACK_FUNCS(backup_csum_root_gen, struct btrfs_root_backup,
                    csum_root_gen, 64)
 BTRFS_SETGET_STACK_FUNCS(backup_csum_root_level, struct btrfs_root_backup,
                    csum_root_level, 8)
 BTRFS_SETGET_STACK_FUNCS(backup_total_bytes, struct btrfs_root_backup,
                    total_bytes, 64)
 BTRFS_SETGET_STACK_FUNCS(backup_bytes_used, struct btrfs_root_backup,
                    bytes_used, 64)
 BTRFS_SETGET_STACK_FUNCS(backup_num_devices, struct btrfs_root_backup,
                    num_devices, 64)

 /* struct btrfs_super_block */

 BTRFS_SETGET_STACK_FUNCS(super_bytenr, struct btrfs_super_block, bytenr, 64)
 BTRFS_SETGET_STACK_FUNCS(super_flags, struct btrfs_super_block, flags, 64)
 BTRFS_SETGET_STACK_FUNCS(super_generation, struct btrfs_super_block,
                          generation, 64)
 BTRFS_SETGET_STACK_FUNCS(super_root, struct btrfs_super_block, root, 64)
 BTRFS_SETGET_STACK_FUNCS(super_sys_array_size,
                          struct btrfs_super_block, sys_chunk_array_size, 32)
 BTRFS_SETGET_STACK_FUNCS(super_chunk_root_generation,
                          struct btrfs_super_block, chunk_root_generation, 64)
 BTRFS_SETGET_STACK_FUNCS(super_root_level, struct btrfs_super_block,
                          root_level, 8)
 BTRFS_SETGET_STACK_FUNCS(super_chunk_root, struct btrfs_super_block,
                          chunk_root, 64)
 BTRFS_SETGET_STACK_FUNCS(super_chunk_root_level, struct btrfs_super_block,
                          chunk_root_level, 8)
 BTRFS_SETGET_STACK_FUNCS(super_log_root, struct btrfs_super_block,
                          log_root, 64)
 BTRFS_SETGET_STACK_FUNCS(super_log_root_transid, struct btrfs_super_block,
                          log_root_transid, 64)
 BTRFS_SETGET_STACK_FUNCS(super_log_root_level, struct btrfs_super_block,
                          log_root_level, 8)
 BTRFS_SETGET_STACK_FUNCS(super_total_bytes, struct btrfs_super_block,
                          total_bytes, 64)
 BTRFS_SETGET_STACK_FUNCS(super_bytes_used, struct btrfs_super_block,
                          bytes_used, 64)
 BTRFS_SETGET_STACK_FUNCS(super_sectorsize, struct btrfs_super_block,
                          sectorsize, 32)
 BTRFS_SETGET_STACK_FUNCS(super_nodesize, struct btrfs_super_block,
                          nodesize, 32)
 BTRFS_SETGET_STACK_FUNCS(super_leafsize, struct btrfs_super_block,
                          leafsize, 32)
 BTRFS_SETGET_STACK_FUNCS(super_stripesize, struct btrfs_super_block,
                          stripesize, 32)
 BTRFS_SETGET_STACK_FUNCS(super_root_dir, struct btrfs_super_block,
                          root_dir_objectid, 64)
 BTRFS_SETGET_STACK_FUNCS(super_num_devices, struct btrfs_super_block,
                          num_devices, 64)
 BTRFS_SETGET_STACK_FUNCS(super_compat_flags, struct btrfs_super_block,
                          compat_flags, 64)
 BTRFS_SETGET_STACK_FUNCS(super_compat_ro_flags, struct btrfs_super_block,
                          compat_flags, 64)
 BTRFS_SETGET_STACK_FUNCS(super_incompat_flags, struct btrfs_super_block,
                          incompat_flags, 64)
 BTRFS_SETGET_STACK_FUNCS(super_csum_type, struct btrfs_super_block,
                          csum_type, 16)
 BTRFS_SETGET_STACK_FUNCS(super_cache_generation, struct btrfs_super_block,
                          cache_generation, 64)

 static inline int btrfs_super_csum_size(struct btrfs_super_block *s)
 {
         int t = btrfs_super_csum_type(s);
         BUG_ON(t >= (int)ARRAY_SIZE(btrfs_csum_sizes));
         return btrfs_csum_sizes[t];
 }

 static inline unsigned long btrfs_leaf_data(struct extent_buffer *)
 {
         return offsetof(struct btrfs_leaf, items);
 }

 /* struct btrfs_file_extent_item */
 BTRFS_SETGET_FUNCS(file_extent_type, struct btrfs_file_extent_item, type, 8)
 BTRFS_SETGET_STACK_FUNCS(stack_file_extent_type, struct btrfs_file_extent_item, type, 8)

 static inline unsigned long btrfs_file_extent_inline_start(struct
                                                    btrfs_file_extent_item *e)
 {
         unsigned long offset = (unsigned long)e;
         offset += offsetof(struct btrfs_file_extent_item, disk_bytenr);
         return offset;
 }

 static inline u32 btrfs_file_extent_calc_inline_size(u32 datasize)
 {
         return offsetof(struct btrfs_file_extent_item, disk_bytenr) + datasize;
 }

 BTRFS_SETGET_FUNCS(file_extent_disk_bytenr, struct btrfs_file_extent_item,
                    disk_bytenr, 64)
 BTRFS_SETGET_STACK_FUNCS(stack_file_extent_disk_bytenr, struct btrfs_file_extent_item,
                    disk_bytenr, 64)
 BTRFS_SETGET_FUNCS(file_extent_generation, struct btrfs_file_extent_item,
                    generation, 64)
 BTRFS_SETGET_STACK_FUNCS(stack_file_extent_generation, struct btrfs_file_extent_item,
                    generation, 64)
 BTRFS_SETGET_FUNCS(file_extent_disk_num_bytes, struct btrfs_file_extent_item,
                    disk_num_bytes, 64)
 BTRFS_SETGET_FUNCS(file_extent_offset, struct btrfs_file_extent_item,
                   offset, 64)
 BTRFS_SETGET_STACK_FUNCS(stack_file_extent_offset, struct btrfs_file_extent_item,
                   offset, 64)
 BTRFS_SETGET_FUNCS(file_extent_num_bytes, struct btrfs_file_extent_item,
                    num_bytes, 64)
 BTRFS_SETGET_STACK_FUNCS(stack_file_extent_num_bytes, struct btrfs_file_extent_item,
                    num_bytes, 64)
 BTRFS_SETGET_FUNCS(file_extent_ram_bytes, struct btrfs_file_extent_item,
                    ram_bytes, 64)
 BTRFS_SETGET_STACK_FUNCS(stack_file_extent_ram_bytes, struct btrfs_file_extent_item,
                    ram_bytes, 64)
 BTRFS_SETGET_FUNCS(file_extent_compression, struct btrfs_file_extent_item,
                    compression, 8)
 BTRFS_SETGET_STACK_FUNCS(stack_file_extent_compression, struct btrfs_file_extent_item,
                    compression, 8)
 BTRFS_SETGET_FUNCS(file_extent_encryption, struct btrfs_file_extent_item,
                    encryption, 8)
 BTRFS_SETGET_FUNCS(file_extent_other_encoding, struct btrfs_file_extent_item,
                    other_encoding, 16)

 /* btrfs_qgroup_status_item */
 BTRFS_SETGET_FUNCS(qgroup_status_version, struct btrfs_qgroup_status_item,
                    version, 64)
 BTRFS_SETGET_FUNCS(qgroup_status_generation, struct btrfs_qgroup_status_item,
                    generation, 64)
 BTRFS_SETGET_FUNCS(qgroup_status_flags, struct btrfs_qgroup_status_item,
                    flags, 64)
 BTRFS_SETGET_FUNCS(qgroup_status_scan, struct btrfs_qgroup_status_item,
                    scan, 64)

 /* btrfs_qgroup_info_item */
 BTRFS_SETGET_FUNCS(qgroup_info_generation, struct btrfs_qgroup_info_item,
                    generation, 64)
 BTRFS_SETGET_FUNCS(qgroup_info_referenced, struct btrfs_qgroup_info_item,
                    referenced, 64)
 BTRFS_SETGET_FUNCS(qgroup_info_referenced_compressed,
                    struct btrfs_qgroup_info_item, referenced_compressed, 64)
 BTRFS_SETGET_FUNCS(qgroup_info_exclusive, struct btrfs_qgroup_info_item,
                    exclusive, 64)
 BTRFS_SETGET_FUNCS(qgroup_info_exclusive_compressed,
                    struct btrfs_qgroup_info_item, exclusive_compressed, 64)

 BTRFS_SETGET_STACK_FUNCS(stack_qgroup_info_generation,
                          struct btrfs_qgroup_info_item, generation, 64)
 BTRFS_SETGET_STACK_FUNCS(stack_qgroup_info_referenced,
                          struct btrfs_qgroup_info_item, referenced, 64)
 BTRFS_SETGET_STACK_FUNCS(stack_qgroup_info_referenced_compressed,
                    struct btrfs_qgroup_info_item, referenced_compressed, 64)
 BTRFS_SETGET_STACK_FUNCS(stack_qgroup_info_exclusive,
                          struct btrfs_qgroup_info_item, exclusive, 64)
 BTRFS_SETGET_STACK_FUNCS(stack_qgroup_info_exclusive_compressed,
                    struct btrfs_qgroup_info_item, exclusive_compressed, 64)

 /* btrfs_qgroup_limit_item */
 BTRFS_SETGET_FUNCS(qgroup_limit_flags, struct btrfs_qgroup_limit_item,
                    flags, 64)
 BTRFS_SETGET_FUNCS(qgroup_limit_max_referenced, struct btrfs_qgroup_limit_item,
                    max_referenced, 64)
 BTRFS_SETGET_FUNCS(qgroup_limit_max_exclusive, struct btrfs_qgroup_limit_item,
                    max_exclusive, 64)
 BTRFS_SETGET_FUNCS(qgroup_limit_rsv_referenced, struct btrfs_qgroup_limit_item,
                    rsv_referenced, 64)
 BTRFS_SETGET_FUNCS(qgroup_limit_rsv_exclusive, struct btrfs_qgroup_limit_item,
                    rsv_exclusive, 64)

 /* this returns the number of file bytes represented by the inline item.
  * If an item is compressed, this is the uncompressed size
  */
 static inline u32 btrfs_file_extent_inline_len(struct extent_buffer *eb,
                                         struct btrfs_file_extent_item *e)
 {
        return btrfs_file_extent_ram_bytes(eb, e);
 }

 /*
  * this returns the number of bytes used by the item on disk, minus the
  * size of any extent headers.  If a file is compressed on disk, this is
  * the compressed size
  */
 static inline u32 btrfs_file_extent_inline_item_len(struct extent_buffer *eb,
                                                     struct btrfs_item *e)
 {
        unsigned long offset;
        offset = offsetof(struct btrfs_file_extent_item, disk_bytenr);
        return btrfs_item_size(eb, e) - offset;
 }

 static inline u32 btrfs_level_size(struct btrfs_root *root, int level) {
         if (level == 0)
                 return root->leafsize;
         return root->nodesize;
 }

 /* helper function to cast into the data area of the leaf. */
 #define btrfs_item_ptr(leaf, slot, type) \
         ((type *)(btrfs_leaf_data(leaf) + \
         btrfs_item_offset_nr(leaf, slot)))

 #define btrfs_item_ptr_offset(leaf, slot) \
         ((unsigned long)(btrfs_leaf_data(leaf) + \
         btrfs_item_offset_nr(leaf, slot)))

 /* extent-tree.c */
 int btrfs_fix_block_accounting(struct btrfs_trans_handle *trans,
                                  struct btrfs_root *root);
 int btrfs_check_block_accounting(struct btrfs_root *root);
 void btrfs_pin_extent(struct btrfs_fs_info *fs_info, u64 bytenr, u64 num_bytes);
 int btrfs_extent_post_op(struct btrfs_trans_handle *trans,
                          struct btrfs_root *root);
 int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy);
 struct btrfs_block_group_cache *btrfs_lookup_block_group(struct
                                                          btrfs_fs_info *info,
                                                          u64 bytenr);
 struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root,
                                                  struct btrfs_block_group_cache
                                                  *hint, u64 search_start,
                                                  int data, int owner);
 struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
                                         struct btrfs_root *root,
                                         u32 blocksize, u64 root_objectid,
                                         struct btrfs_disk_key *key, int level,
                                         u64 hint, u64 empty_size);
 int btrfs_alloc_extent(struct btrfs_trans_handle *trans,
                        struct btrfs_root *root,
                        u64 num_bytes, u64 parent,
                        u64 root_objectid, u64 ref_generation,
                        u64 owner, u64 empty_size, u64 hint_byte,
                        u64 search_end, struct btrfs_key *ins, int data);
 int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
                              struct btrfs_root *root, u64 bytenr,
                              u64 num_bytes, u64 *refs, u64 *flags);
 int btrfs_set_block_flags(struct btrfs_trans_handle *trans,
                           struct btrfs_root *root,
                           u64 bytenr, u64 num_bytes, u64 flags);
 int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                   struct extent_buffer *buf, int record_parent);
 int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                   struct extent_buffer *buf, int record_parent);
 int btrfs_free_extent(struct btrfs_trans_handle *trans,
                       struct btrfs_root *root,
                       u64 bytenr, u64 num_bytes, u64 parent,
                       u64 root_objectid, u64 owner, u64 offset);
 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
                                struct btrfs_root *root,
                                struct extent_io_tree *unpin);
 int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
                                 struct btrfs_root *root,
                                 u64 bytenr, u64 num_bytes, u64 parent,
                                 u64 root_objectid, u64 ref_generation,
                                 u64 owner_objectid);
 int btrfs_update_extent_ref(struct btrfs_trans_handle *trans,
                             struct btrfs_root *root, u64 bytenr,
                             u64 orig_parent, u64 parent,
                             u64 root_objectid, u64 ref_generation,
                             u64 owner_objectid);
 int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans,
                                     struct btrfs_root *root);
 int btrfs_free_block_groups(struct btrfs_fs_info *info);
 int btrfs_read_block_groups(struct btrfs_root *root);
 int btrfs_make_block_group(struct btrfs_trans_handle *trans,
                            struct btrfs_root *root, u64 bytes_used,
                            u64 type, u64 chunk_objectid, u64 chunk_offset,
                            u64 size);
 int btrfs_make_block_groups(struct btrfs_trans_handle *trans,
                             struct btrfs_root *root);
 int btrfs_update_block_group(struct btrfs_trans_handle *trans,
                              struct btrfs_root *root, u64 bytenr, u64 num,
                              int alloc, int mark_free);
 /* ctree.c */
 int btrfs_del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                    struct btrfs_path *path, int level, int slot);
 int btrfs_check_node(struct btrfs_root *root,
                       struct btrfs_disk_key *parent_key,
                       struct extent_buffer *buf);
 int btrfs_check_leaf(struct btrfs_root *root,
                       struct btrfs_disk_key *parent_key,
                       struct extent_buffer *buf);
 int btrfs_fsck_reinit_root(struct btrfs_trans_handle *trans,
                       struct btrfs_root *root);
 void reada_for_search(struct btrfs_root *root, struct btrfs_path *path,
                              int level, int slot, u64 objectid);
 struct extent_buffer *read_node_slot(struct btrfs_root *root,
                                    struct extent_buffer *parent, int slot);
 int btrfs_previous_item(struct btrfs_root *root,
                         struct btrfs_path *path, u64 min_objectid,
                         int type);
 int btrfs_comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2);
 int btrfs_cow_block(struct btrfs_trans_handle *trans,
                     struct btrfs_root *root, struct extent_buffer *buf,
                     struct extent_buffer *parent, int parent_slot,
                     struct extent_buffer **cow_ret);
 int __btrfs_cow_block(struct btrfs_trans_handle *trans,
                              struct btrfs_root *root,
                              struct extent_buffer *buf,
                              struct extent_buffer *parent, int parent_slot,
                              struct extent_buffer **cow_ret,
                              u64 search_start, u64 empty_size);
 int btrfs_copy_root(struct btrfs_trans_handle *trans,
                       struct btrfs_root *root,
                       struct extent_buffer *buf,
                       struct extent_buffer **cow_ret, u64 new_root_objectid);
 int btrfs_extend_item(struct btrfs_trans_handle *trans, struct btrfs_root
                       *root, struct btrfs_path *path, u32 data_size);
 int btrfs_truncate_item(struct btrfs_trans_handle *trans,
                         struct btrfs_root *root,
                         struct btrfs_path *path,
                         u32 new_size, int from_end);
 int btrfs_split_item(struct btrfs_trans_handle *trans,
                      struct btrfs_root *root,
                      struct btrfs_path *path,
                      struct btrfs_key *new_key,
                      unsigned long split_offset);
 int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
                       *root, struct btrfs_key *key, struct btrfs_path *p, int
                       ins_len, int cow);
 int btrfs_realloc_node(struct btrfs_trans_handle *trans,
                        struct btrfs_root *root, struct extent_buffer *parent,
                        int start_slot, int cache_only, u64 *last_ret,
                        struct btrfs_key *progress);
 void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p);
 struct btrfs_path *btrfs_alloc_path(void);
 void btrfs_free_path(struct btrfs_path *p);
 void btrfs_init_path(struct btrfs_path *p);
 int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                    struct btrfs_path *path, int slot, int nr);

 static inline int btrfs_del_item(struct btrfs_trans_handle *trans,
                                  struct btrfs_root *root,
                                  struct btrfs_path *path)
 {
         return btrfs_del_items(trans, root, path, path->slots[0], 1);
 }

 int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
                       *root, struct btrfs_key *key, void *data, u32 data_size);
 int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
                              struct btrfs_root *root,
                              struct btrfs_path *path,
                              struct btrfs_key *cpu_key, u32 *data_size, int nr);

 static inline int btrfs_insert_empty_item(struct btrfs_trans_handle *trans,
                                           struct btrfs_root *root,
                                           struct btrfs_path *path,
                                           struct btrfs_key *key,
                                           u32 data_size)
 {
         return btrfs_insert_empty_items(trans, root, path, key, &data_size, 1);
 }

 int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path);
 int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path);
 int btrfs_leaf_free_space(struct btrfs_root *root, struct extent_buffer *leaf);
 int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root
                         *root);
 int btrfs_set_item_key_safe(struct btrfs_trans_handle *trans,
                             struct btrfs_root *root, struct btrfs_path *path,
                             struct btrfs_key *new_key);

 /* root-item.c */
 int btrfs_add_root_ref(struct btrfs_trans_handle *trans,
                        struct btrfs_root *tree_root,
                        u64 root_id, u8 type, u64 ref_id,
                        u64 dirid, u64 sequence,
                        const char *name, int name_len);
 int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                    struct btrfs_key *key);
 int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root
                       *root, struct btrfs_key *key, struct btrfs_root_item
                       *item);
 int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root
                       *root, struct btrfs_key *key, struct btrfs_root_item
                       *item);
 int btrfs_find_last_root(struct btrfs_root *root, u64 objectid, struct
                          btrfs_root_item *item, struct btrfs_key *key);
 int btrfs_find_dead_roots(struct btrfs_root *root, u64 objectid,
                           struct btrfs_root *latest_root);
 /* dir-item.c */
 int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
                           *root, const char *name, int name_len, u64 dir,
                           struct btrfs_key *location, u8 type, u64 index);
 struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans,
                                              struct btrfs_root *root,
                                              struct btrfs_path *path, u64 dir,
                                              const char *name, int name_len,
                                              int mod);
 struct btrfs_dir_item *
 btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans,
                             struct btrfs_root *root,
                             struct btrfs_path *path, u64 dir,
                             u64 objectid, const char *name, int name_len,
                             int mod);
 struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_root *root,
                               struct btrfs_path *path,
                               const char *name, int name_len);
 int btrfs_delete_one_dir_name(struct btrfs_trans_handle *trans,
                               struct btrfs_root *root,
                               struct btrfs_path *path,
                               struct btrfs_dir_item *di);
 int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans,
                             struct btrfs_root *root, const char *name,
                             u16 name_len, const void *data, u16 data_len,
                             u64 dir);
 struct btrfs_dir_item *btrfs_lookup_xattr(struct btrfs_trans_handle *trans,
                                           struct btrfs_root *root,
                                           struct btrfs_path *path, u64 dir,
                                           const char *name, u16 name_len,
                                           int mod);
 /* inode-map.c */
 int btrfs_find_free_objectid(struct btrfs_trans_handle *trans,
                              struct btrfs_root *fs_root,
                              u64 dirid, u64 *objectid);
 int btrfs_find_highest_inode(struct btrfs_root *fs_root, u64 *objectid);

 /* inode-item.c */
 int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
                            struct btrfs_root *root,
                            const char *name, int name_len,
                            u64 inode_objectid, u64 ref_objectid, u64 index);
 int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
                            struct btrfs_root *root,
                            const char *name, int name_len,
                            u64 inode_objectid, u64 ref_objectid);
 int btrfs_insert_empty_inode(struct btrfs_trans_handle *trans,
                              struct btrfs_root *root,
                              struct btrfs_path *path, u64 objectid);
 int btrfs_insert_inode(struct btrfs_trans_handle *trans, struct btrfs_root
                        *root, u64 objectid, struct btrfs_inode_item
                        *inode_item);
 int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root
                        *root, struct btrfs_path *path,
                        struct btrfs_key *location, int mod);

 /* file-item.c */
 int btrfs_del_csums(struct btrfs_trans_handle *trans,
                     struct btrfs_root *root, u64 bytenr, u64 len);
 int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
                              struct btrfs_root *root,
                              u64 objectid, u64 pos, u64 offset,
                              u64 disk_num_bytes,
                              u64 num_bytes);
 int btrfs_insert_inline_extent(struct btrfs_trans_handle *trans,
                                 struct btrfs_root *root, u64 objectid,
                                 u64 offset, char *buffer, size_t size);
 int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
                              struct btrfs_root *root,
                              struct btrfs_path *path, u64 objectid,
                              u64 bytenr, int mod);
 int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
                           struct btrfs_root *root, u64 alloc_end,
                           u64 bytenr, char *data, size_t len);
 struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
                                           struct btrfs_root *root,
                                           struct btrfs_path *path,
                                           u64 bytenr, int cow);
 int btrfs_csum_truncate(struct btrfs_trans_handle *trans,
                         struct btrfs_root *root, struct btrfs_path *path,
                         u64 isize);
 #endif
